According to conventional inspection systems of this type, various products such as, for example, chemicals or electronic components, are inspected as test samples with a high accuracy by means of various non-contact type inspection devices which utilize, for example, the transmissivity or reflectivity of light, to prevent distribution of products of poor quality to commodity distribution channels (see Japanese Examined Patent Publication No. Showa 47-10466, Japanese Unexamined Patent Publication (Kokai) No. Showa 50-11094, Japanese Examined Patent Publication No. Showa 57-11416, Japanese Unexamined Patent Publication (Kokai) No. Showa 57-142252, Japanese Examined Patent Publication No. Showa 60-20695, Japanese Unexamined Patent Publication (Kokai) No. Showa 60-98341, Japanese Unexamined Patent Publication (Kokai) No. Showa 61-282219, Japanese Examined Patent Publication No. Showa 62-15821, Japanese Unexamined Patent Publication (Kokai) No. Showa 64-31040 and Japanese Unexamined Patent Publication (Kokai) No. Heisei 3-96841).
According to a conventional non-contact type inspection system, test samples are conveyed so as to pass a photographing area of an inspection device, e.g. CCD camera, then is each photographed by the CCD camera and the image thus obtained is processed by an image processor to check the quality of the test sample.
In such a conventional non-contact type inspection system, if the test samples are transparent containers made of glass or a plastic material such as, for example, ampoules or vials which contain chemicals, food or drink, light is passed through each of the containers, using an optical inspection device, and is photographed by the CCD camera, whereby even whether a foreign matter is mixed in the inside liquid of each container can be judged precisely.
FIGS. 10 and 11 illustrate a principal portion of a conventional non-contact type inspection system 2 wherein test samples are ampoules 1. The ampoules 1 are conveyed while being put on seats 3a formed on a rotary table 3. A table 8 is disposed inside the rotary table 3 which conveys the ampoules 1, while a table 8a is disposed outside the rotary table 3. Light is emitted from an electric light 4 disposed on the inner table 8 and is passed through each ampoule 1 from the back side of the ampoule 1, then is photographed by a CCD camera 5 disposed on the outer table 8a.
The inspection system 2 is provided with caps 6 whereby the ampoules 1 being conveyed with rotation of the rotary table 3 are pressed from above and are thereby held stably. The caps 6 are attached a large number to the upper portion of a cylindrical drum 7 in the circumferential direction of the drum 7. The drum 7, which is mounted on the rotary table 3 integrally, is rotated together with the rotary table 3 so that the caps 6 can move rotatively together with the ampoules 1 which are moved rotatively. The caps 6 can move vertically through sliding rods 6a to receive and subsequently hold the ampoules 1.
In the conventional non-contact type inspection system 2, the drum 7, which is mounted on the rotary table 3 for co-rotation with the same table 3, has a cylindrical wall 7a, and this cylindrical wall 7a, located behind the ampoules 1, shields the ampoules 1 from the electric light 4. Therefore, for causing the light from the electric light 4 to pass through the ampoules 1 in the inspection work, slits 9 are formed in the cylindrical wall 7a in positions corresponding to the positions of the caps 6, allowing the light from the electric light 4 to be radiated to the backs of the ampoules 1.
However, the quantity of light radiated through the slits 9 formed in the cylindrical wall 7a is limited, and the slits 9 limits the irradiation angle. Consequently, the layout of the CCD camera 5 to be disposed in corresponding relation to the electric light 4 is also limited. Thus, there has been the problem that the inspection cannot be done with a high accuracy and over a wide range.